In a blow molding machine, a mold must be replaced according containers to be blow molded. As a blow mold for blow molding a container from a preform, a pair of blow cavity split molds is necessary. In addition, in order that the bottom portion of a blow molded container can have a so called champagne bottom shape, a self-supporting bottle shape or a similar shape projecting inwardly, a raised bottom mold is necessary as a blow mold. Also, in some cases, separately from the pair of blow cavity split molds, a raised bottom mold which is clamped by the pair of blow cavity split molds is necessary.
Patent document 1 discloses a blow mold unit in which a pair of blow cavity and a raised bottom mold can be handled as an integral body when replacing molds.